Competitors in trick, jump, and slalom ski and wakeboard events require tow boats capable of consistent and accurate speed control. Successful completion of slalom and jump runs require passes through a competition water course at a precise specific speed. Competition rules usually require that such speed requirements be confirmed by use of a speed measurement system. For example, American Water Ski Association Three-Event Slalom and Jump competitions specify a required time window for completion of all segments of the course to confirm that speed was maintained as required throughout the pass. These times have historically been measured either using manual stopwatch measurements or, more recently, using magnetic sensors which are triggered by the presence of magnets attached to buoys in the water that are in close proximity to the path of the tow boat at the required timing measurement points in the course. Course times are reported and logged for every individual pass in competition. Reliability of triggering the magnetic sensor, as well as maintenance of the magnets attached to the buoys, has consistently caused major difficulties in running competitive 3-event competitions.